[PATCH v5 0/2] phy: add basic support for NXPs TJA1145 CAN transceiver

[PATCH v5 0/2] phy: add basic support for NXPs TJA1145 CAN transceiver

[Dimitri Fedrau via B4 Relay]

Add basic driver support for NXPs TJA1145 CAN transceiver which brings the
PHY up/down by switching to normal/standby mode using SPI commands.

Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
Changes in v5:
- No functional change, basically a resend with added tags
- fixed typo in define TJA1145_MODE_CRTL_STBY to TJA1145_MODE_CTRL_STBY
  and TJA1145_MODE_CRTL_NORMAL to TJA1145_MODE_CTRL_NORMAL
- remove unneeded include -#include <linux/bitfield.h>
- added owner to tja1145_phy_ops
- Link to v4: https://lore.kernel.org/r/20251015-tja1145-support-v4-0-4d3ca13c8881@liebherr.com

Changes in v4:
- Change compatible to: nxp,tja1145 (Connor)
- Mark spi-cpha as required (Connor)
- Switch from unevaluatedProperties: false to
  additionalProperties: false (Connor)
- Remove double newline after tja1145_rd_table (Marc)
- Link to v3: https://lore.kernel.org/r/20251013-tja1145-support-v3-0-4a9d245fe067@liebherr.com

Changes in v3:
- bindings: fix SPI bus unit address format error
- bindings: added resolution of discussion into commit msg
- Checked binding with:
  make dt_binding_check DT_SCHEMA_FILES=nxp,tja1145-can.yaml
  Missed it for V2, didn't do it intentionally. Sorry.
- Link to v2: https://lore.kernel.org/r/20250829-tja1145-support-v2-0-60997f328979@liebherr.com

Changes in v2:
- bindings: Change node name in example to can-phy
- bindings: Fix order of properties, reg property is second
- bindings: Change compatible to match filename
- change compatible to nxp,tja1145-can
- Link to v1: https://lore.kernel.org/r/20250728-tja1145-support-v1-0-ebd8494d545c@liebherr.com

---
Dimitri Fedrau (2):
      dt-bindings: phy: add support for NXPs TJA1145 CAN transceiver
      phy: add basic support for NXPs TJA1145 CAN transceiver

 .../devicetree/bindings/phy/nxp,tja1145.yaml       |  80 +++++++++
 drivers/phy/Kconfig                                |  10 ++
 drivers/phy/Makefile                               |   1 +
 drivers/phy/phy-nxp-tja1145.c                      | 184 +++++++++++++++++++++
 4 files changed, 275 insertions(+)
---
base-commit: 29b4d8a7637f027b538787896bee520f2dacc904
change-id: 20250726-tja1145-support-d6ccdc4d2da3

Best regards,
-- 
Dimitri Fedrau <dimitri.fedrau@liebherr.com>

[PATCH v5 1/2] dt-bindings: phy: add support for NXPs TJA1145 CAN transceiver

[Dimitri Fedrau via B4 Relay]

From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Adding documentation for NXPs TJA1145 CAN transceiver, which resides like
the ti,tcan104x-can.yaml in the same directory as other generic PHY
subsystem bindings. At the moment there is only support for simple PHYs
by using regulator bindings in combination with can-transceiver.yaml or
PHYs that implement the generic PHY subsystem like the NXP TJA1145.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
 .../devicetree/bindings/phy/nxp,tja1145.yaml       | 80 ++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/nxp,tja1145.yaml b/Documentation/devicetree/bindings/phy/nxp,tja1145.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..46de6d0f2dd9b9fd41c97eb4c9340e3ac36090a3
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/nxp,tja1145.yaml
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/nxp,tja1145.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TJA1145 CAN transceiver
+
+maintainers:
+  - Dimitri Fedrau <dimitri.fedrau@liebherr.com>
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: nxp,tja1145
+
+  reg:
+    maxItems: 1
+
+  "#phy-cells":
+    const: 0
+
+  spi-cpha: true
+
+  spi-max-frequency:
+    maximum: 4000000
+
+  spi-cs-setup-delay-ns:
+    minimum: 50
+    default: 50
+
+  spi-cs-hold-delay-ns:
+    minimum: 50
+    default: 50
+
+  spi-cs-inactive-delay-ns:
+    minimum: 250
+    default: 250
+
+  vcc-supply:
+    description:
+      CAN transceiver supply voltage
+
+  vio-supply:
+    description:
+      Supply voltage for I/O level adaptor
+
+  vbat-supply:
+    description:
+      Battery supply voltage
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+  - spi-cpha
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        can-phy@0 {
+            compatible = "nxp,tja1145";
+            reg = <0>;
+            #phy-cells = <0>;
+            spi-cpha;
+            spi-max-frequency = <4000000>;
+            spi-cs-setup-delay-ns = <50>;
+            spi-cs-hold-delay-ns = <50>;
+            spi-cs-inactive-delay-ns = <250>;
+            vcc-supply = <&reg_5v0>;
+            vio-supply = <&reg_3v3>;
+            vbat-supply = <&reg_24v0>;
+        };
+    };

-- 
2.39.5

Re: [PATCH v5 1/2] dt-bindings: phy: add support for NXPs TJA1145 CAN transceiver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] The dt-binding omits support for the `max-bitrate` property.
- [Medium] The dt-binding omits support for the `interrupts` property for wake-up routing.
--

commit 853ad7c93ebe1c2a625ddddde401c4aaad496a8e
Author: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

dt-bindings: phy: add support for NXPs TJA1145 CAN transceiver

This commit adds documentation for the NXP TJA1145 CAN transceiver, residing
in the generic PHY subsystem bindings. It describes the required SPI
configurations and supply properties for the device.

> diff --git a/Documentation/devicetree/bindings/phy/nxp,tja1145.yaml b/Documentation/devicetree/bindings/phy/nxp,tja1145.yaml
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/nxp,tja1145.yaml

[ ... ]

> +  vbat-supply:
> +    description:
> +      Battery supply voltage
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#phy-cells"
> +  - spi-cpha
> +
> +additionalProperties: false

Does this binding need to include the max-bitrate property?

This property is standard for CAN transceivers to describe board-level
capability constraints where the layout cannot support the chip's theoretical
maximum speed. Since additionalProperties is set to false, valid device trees
specifying a maximum bitrate will fail validation.

Also, does this device tree binding need support for the interrupts property?

The TJA1145 supports partial networking and wake-up functionality, which can
route a wake-up signal to an interrupt line on the host processor. With
additionalProperties set to false, it is impossible to describe this hardware
interrupt routing in the device tree.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260513-tja1145-support-v5-0-38720a7ee63e@liebherr.com?part=1

[PATCH v5 2/2] phy: add basic support for NXPs TJA1145 CAN transceiver

[Dimitri Fedrau via B4 Relay]

From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Add basic driver support for NXPs TJA1145 CAN transceiver which brings the
PHY up/down by switching to normal/standby mode using SPI commands.

Tested-by: <lee.lockhey@gmail.com>
Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
 drivers/phy/Kconfig           |  10 +++
 drivers/phy/Makefile          |   1 +
 drivers/phy/phy-nxp-tja1145.c | 184 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 195 insertions(+)

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index ab96ee5858c1a9dee2aea3a896c09b397cc30c7f..a3f9a05e222002e23d5080aa22b56f2a822a4b97 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -124,6 +124,16 @@ config PHY_NXP_PTN3222
 	  schemes. It supports all three USB 2.0 data rates: Low Speed, Full
 	  Speed and High Speed.
 
+config PHY_NXP_TJA1145
+	tristate "NXP TJA1145 CAN transceiver PHY"
+	select GENERIC_PHY
+	select REGMAP_SPI
+	depends on SPI
+	help
+	  This option enables support for NXPs TJA1145 CAN transceiver as a PHY.
+	  This driver provides function for putting the transceiver in various
+	  functional modes using SPI commands.
+
 config PHY_PISTACHIO_USB
 	tristate "IMG Pistachio USB2.0 PHY driver"
 	depends on MIPS || COMPILE_TEST
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index f31767745123773757e84b0b5fb85ec286c1d977..65ea9f0bc7f151378caa6e161f8b8a5c6884d7e5 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_PHY_GOOGLE_USB)		+= phy-google-usb.o
 obj-$(CONFIG_USB_LGM_PHY)		+= phy-lgm-usb.o
 obj-$(CONFIG_PHY_LPC18XX_USB_OTG)	+= phy-lpc18xx-usb-otg.o
 obj-$(CONFIG_PHY_NXP_PTN3222)		+= phy-nxp-ptn3222.o
+obj-$(CONFIG_PHY_NXP_TJA1145)		+= phy-nxp-tja1145.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_SNPS_EUSB2)		+= phy-snps-eusb2.o
 obj-$(CONFIG_PHY_XGENE)			+= phy-xgene.o
diff --git a/drivers/phy/phy-nxp-tja1145.c b/drivers/phy/phy-nxp-tja1145.c
new file mode 100644
index 0000000000000000000000000000000000000000..1e8bd169743abfaeee6948d200e6ac320cd616ff
--- /dev/null
+++ b/drivers/phy/phy-nxp-tja1145.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Liebherr-Electronics and Drives GmbH
+ */
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/phy/phy.h>
+#include <linux/spi/spi.h>
+
+#define TJA1145_MODE_CTRL		0x01
+#define TJA1145_MODE_CTRL_MC		GENMASK(2, 0)
+#define TJA1145_MODE_CTRL_STBY		BIT(2)
+#define TJA1145_MODE_CTRL_NORMAL	TJA1145_MODE_CTRL_MC
+
+#define TJA1145_CAN_CTRL		0x20
+#define TJA1145_CAN_CTRL_CMC		GENMASK(1, 0)
+#define TJA1145_CAN_CTRL_ACTIVE		BIT(1)
+
+#define TJA1145_IDENT			0x7e
+#define TJA1145_IDENT_TJA1145T		0x70
+
+#define TJA1145_SPI_READ_BIT		BIT(0)
+#define TJA1145T_MAX_BITRATE		1000000
+
+static int tja1145_phy_power_on(struct phy *phy)
+{
+	struct regmap *map = phy_get_drvdata(phy);
+	int ret;
+
+	/*
+	 * Switch operating mode to normal which is the active operating mode.
+	 * In this mode, the device is fully operational.
+	 */
+	ret = regmap_update_bits(map, TJA1145_MODE_CTRL, TJA1145_MODE_CTRL_MC,
+				 TJA1145_MODE_CTRL_NORMAL);
+	if (ret)
+		return ret;
+
+	/*
+	 * Switch to CAN operating mode active where the PHY can transmit and
+	 * receive data.
+	 */
+	return regmap_update_bits(map, TJA1145_CAN_CTRL, TJA1145_CAN_CTRL_CMC,
+				  TJA1145_CAN_CTRL_ACTIVE);
+}
+
+static int tja1145_phy_power_off(struct phy *phy)
+{
+	struct regmap *map = phy_get_drvdata(phy);
+
+	/*
+	 * Switch to operating mode standby, the PHY is unable to transmit or
+	 * receive data in standby mode.
+	 */
+	return regmap_update_bits(map, TJA1145_MODE_CTRL, TJA1145_MODE_CTRL_MC,
+				  TJA1145_MODE_CTRL_STBY);
+}
+
+static const struct phy_ops tja1145_phy_ops = {
+	.power_on = tja1145_phy_power_on,
+	.power_off = tja1145_phy_power_off,
+	.owner = THIS_MODULE,
+};
+
+static const struct regmap_range tja1145_wr_holes_ranges[] = {
+	regmap_reg_range(0x00, 0x00),
+	regmap_reg_range(0x02, 0x03),
+	regmap_reg_range(0x05, 0x05),
+	regmap_reg_range(0x0b, 0x1f),
+	regmap_reg_range(0x21, 0x22),
+	regmap_reg_range(0x24, 0x25),
+	regmap_reg_range(0x30, 0x4b),
+	regmap_reg_range(0x4d, 0x60),
+	regmap_reg_range(0x62, 0x62),
+	regmap_reg_range(0x65, 0x67),
+	regmap_reg_range(0x70, 0xff),
+};
+
+static const struct regmap_access_table tja1145_wr_table = {
+	.no_ranges = tja1145_wr_holes_ranges,
+	.n_no_ranges = ARRAY_SIZE(tja1145_wr_holes_ranges),
+};
+
+static const struct regmap_range tja1145_rd_holes_ranges[] = {
+	regmap_reg_range(0x00, 0x00),
+	regmap_reg_range(0x02, 0x02),
+	regmap_reg_range(0x05, 0x05),
+	regmap_reg_range(0x0b, 0x1f),
+	regmap_reg_range(0x21, 0x21),
+	regmap_reg_range(0x24, 0x25),
+	regmap_reg_range(0x30, 0x4a),
+	regmap_reg_range(0x4d, 0x5f),
+	regmap_reg_range(0x62, 0x62),
+	regmap_reg_range(0x65, 0x67),
+	regmap_reg_range(0x70, 0x7d),
+	regmap_reg_range(0x7f, 0xff),
+};
+
+static const struct regmap_access_table tja1145_rd_table = {
+	.no_ranges = tja1145_rd_holes_ranges,
+	.n_no_ranges = ARRAY_SIZE(tja1145_rd_holes_ranges),
+};
+
+static const struct regmap_config tja1145_regmap_config = {
+	.reg_bits = 8,
+	.reg_shift = -1,
+	.val_bits = 8,
+	.wr_table = &tja1145_wr_table,
+	.rd_table = &tja1145_rd_table,
+	.read_flag_mask = TJA1145_SPI_READ_BIT,
+	.max_register = TJA1145_IDENT,
+};
+
+static int tja1145_check_ident(struct device *dev, struct regmap *map)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(map, TJA1145_IDENT, &val);
+	if (ret)
+		return ret;
+
+	if (val != TJA1145_IDENT_TJA1145T) {
+		dev_err(dev, "Expected device id: 0x%02x, got: 0x%02x\n",
+			TJA1145_IDENT_TJA1145T, val);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int tja1145_probe(struct spi_device *spi)
+{
+	struct phy_provider *phy_provider;
+	struct device *dev = &spi->dev;
+	struct regmap *map;
+	struct phy *phy;
+	int ret;
+
+	map = devm_regmap_init_spi(spi, &tja1145_regmap_config);
+	if (IS_ERR(map))
+		return dev_err_probe(dev, PTR_ERR(map), "failed to init regmap\n");
+
+	ret = tja1145_check_ident(dev, map);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to identify device\n");
+
+	phy = devm_phy_create(dev, dev->of_node, &tja1145_phy_ops);
+	if (IS_ERR(phy))
+		return dev_err_probe(dev, PTR_ERR(phy), "failed to create PHY\n");
+
+	phy->attrs.max_link_rate = TJA1145T_MAX_BITRATE;
+	phy_set_drvdata(phy, map);
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct spi_device_id tja1145_spi_id[] = {
+	{ "tja1145" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, tja1145_spi_id);
+
+static const struct of_device_id tja1145_of_match[] = {
+	{ .compatible = "nxp,tja1145" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tja1145_of_match);
+
+static struct spi_driver tja1145_driver = {
+	.driver = {
+		.name = "tja1145",
+		.of_match_table = tja1145_of_match,
+	},
+	.probe = tja1145_probe,
+	.id_table = tja1145_spi_id,
+};
+module_spi_driver(tja1145_driver);
+
+MODULE_DESCRIPTION("NXP TJA1145 CAN transceiver PHY driver");
+MODULE_AUTHOR("Dimitri Fedrau <dimitri.fedrau@liebherr.com>");
+MODULE_LICENSE("GPL");

-- 
2.39.5

Re: [PATCH v5 2/2] phy: add basic support for NXPs TJA1145 CAN transceiver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [High] The driver fails to enable the hardware power supplies (`vcc-supply`, `vio-supply`, `vbat-supply`) before communicating with the device.
- [High] The driver does not observe the required mode transition delay when powering on the PHY.
- [Medium] Missing rollback to standby mode in the error path of `tja1145_phy_power_on`.
--

commit 288134e179992cb2e690ff7a97502e72f04e9d5a
Author: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

phy: add basic support for NXPs TJA1145 CAN transceiver

This commit adds basic driver support for the NXP TJA1145 CAN transceiver.
It implements the PHY operations to bring the hardware up and down by
switching between normal and standby modes using SPI commands.

> diff --git a/drivers/phy/phy-nxp-tja1145.c b/drivers/phy/phy-nxp-tja1145.c
> new file mode 100644
> index 0000000000000..1e8bd169743ab
> --- /dev/null
> +++ b/drivers/phy/phy-nxp-tja1145.c

[ ... ]

> +static int tja1145_phy_power_on(struct phy *phy)
> +{
> +	struct regmap *map = phy_get_drvdata(phy);
> +	int ret;
> +
> +	/*
> +	 * Switch operating mode to normal which is the active operating mode.
> +	 * In this mode, the device is fully operational.
> +	 */
> +	ret = regmap_update_bits(map, TJA1145_MODE_CTRL, TJA1145_MODE_CTRL_MC,
> +				 TJA1145_MODE_CTRL_NORMAL);
> +	if (ret)
> +		return ret;

According to the hardware datasheet, transitioning the transceiver to normal
mode can take up to 40 us. Does this sequence need a hardware transition
delay before sending the active mode command?

With a fast SPI bus, the next command might arrive before the hardware state
machine finishes transitioning, which could cause the active mode command to
be ignored.

> +
> +	/*
> +	 * Switch to CAN operating mode active where the PHY can transmit and
> +	 * receive data.
> +	 */
> +	return regmap_update_bits(map, TJA1145_CAN_CTRL, TJA1145_CAN_CTRL_CMC,
> +				  TJA1145_CAN_CTRL_ACTIVE);

If this second regmap_update_bits() fails, the function returns an error
without reverting the device to standby mode.

Since the PHY framework keeps the power_count at 0 on an error return,
phy_power_off() will not be called during shutdown or suspend. Could this
leave the hardware permanently stuck in normal mode, drawing power
unintentionally?

> +}

[ ... ]

> +static int tja1145_probe(struct spi_device *spi)
> +{
> +	struct phy_provider *phy_provider;
> +	struct device *dev = &spi->dev;
> +	struct regmap *map;
> +	struct phy *phy;
> +	int ret;
> +
> +	map = devm_regmap_init_spi(spi, &tja1145_regmap_config);
> +	if (IS_ERR(map))
> +		return dev_err_probe(dev, PTR_ERR(map), "failed to init regmap\n");
> +
> +	ret = tja1145_check_ident(dev, map);

Will this fail to communicate with the hardware on platforms where power
supplies are dynamically controlled?

The device tree binding defines vcc-supply, vio-supply, and vbat-supply as
power sources, but they do not appear to be requested or enabled in this
function before tja1145_check_ident() is called.

This might leave the PHY unpowered, causing the SPI read to return garbage
data and fail the probe with -ENODEV.

> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to identify device\n");

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260513-tja1145-support-v5-0-38720a7ee63e@liebherr.com?part=2